Relief valve



F f WW I a jam. E5, 192 EASQQQE w. ,MCKEE RELIEF VALVE Filed Dec, 9. 1919 PATENT OFFICE.

WILLIAM MCKEE, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO THE CHAPLIN- FULTON MANUFACTURING COMPANY,

PORATION OF PENNSYLVANIA.

OF PITTSBURGH, PENNSYLVANIA, A COR- RELIEF VALVE.

Application filed December 9, 1919. Serial No. 343,528.

To all whom it may concern:

Be it known that I, WILLIAM MCKEE, of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented oertain new and useful Improvements in Relief Valves; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

In the use of orifice meters for the measurement of fluids it is frequently necessary, in order to take care of peak demands, to automatically augment the supply of fluid by cutting in a second meter, it being manifest that only a certain amount of fluid can be delivered at a given pressure through a fixed orifice. This is done by means of a by-pass around the orifice meter in the main line, such by-pass being under the control of an automatic valve.

The primary object of this invention is to provide a simple and highly efficient valve mechanism for controlling the passage through a by-pass line, the valve being automatically opened when the drop in pressure or difierential pressure on the main line reaches a predetermined maximum, and closed when a minimum differential has been reached.

In the drawings, Figure 1 is a vertical sectional view of the improved relief valve. Figure 2 is a view showing a portion of a syst em in which the relief valve is employed, the orifice meters being shown conventionally.

As shown, A designates the main line of a gas supply system; B the inlet and C the outlet, an orifice meter D being located between the inlet and outlet; E a by-pass around the meter D, a second orifice meter F being located in the by-pass.

The means adapted to automatically control passage of the gas through the by-pass includes a casing 1 having an inlet 2 and an outlet 3; a valve 4 having a stem 5 extending upwardly through a packing 6, the upper portion of the valve stem being provided with a collar 7 on which is a circumferential bead or enlargement 8 with which means hereinafter to be described cooperates to hold the valve in fully opened or closed positions. The upper end of the collar 7 is recessed to receive the headed end 9 of the downwardly extending portion of a diaphragm stem 12, the head being retained in the recess with a slight limit of longitudinal play by a gland 13. The upper end of the valve stem 5 and the lower portion of the diaphragm stem, with their connect ing collar 7, are located in a skeleton-like portion 14 of the casing 1 which portion is between the valve chamber. and an upper chamber 15 in which is located a diaphragm 16, the space on the underside of the diahragm being piped to the inlet of the main ine orifice, and the space on the upper-side of the diaphragm being piped to the outlet of the main line orifice. Stufling boxes 17, 18, are provided for the diaphragm stem 12, the extreme upper end of which latter is pivotally connected with a lever 20 fulcrumed at 21 to an upwardly extending link 22 supported by a cap 23 on the casing. On one of the arms of the lever is a weight 24 attached to a grooved roller-bearing sheave 25, movement of the weight on the arm being limited by adjustable stops 26, 27. The position'of these stops on the lever 20 regulates the maximum and minimum diflerential pressures at which the valve shall open and close, the stop 27 being moved to control the pressure at which the valve will open and the stop 26 to control the pressure at which the valve will close. A counterweight 28 is secured to the other arm of the lever for balancing the weight of the moving parts.

The circumferential bead 8 on the collar 7 is part of the means for locking the valve 4 in opened or closed position. Boxes 30 are set in each side of the skeleton portion 14 of the casing, and ineach is a springpressed plunger 31, the outer end of which has a steel ball 32 spun in a housing therefor. The ball end of each plunger is al ways in contact with the collar 7 of the valve, above the circumferential bead when the valve is closed and below it when opened, thus maintaining the valve locked in one or the other of these positions.

The movements of the valve are auto matically controlled by the difference between the pressure at the inlet of the main line orifice and the pressure at the outlet of the main line orifice, the weight 24 assisting in quicklv closing the valve and by its movement on the lever arm permitting the maximum differential to quickly open the valve to full position. When the difierential pressure has reached a maximum, the unbalanced force raises the diaphragm and the weighted outer end of the lever until the latter is in a horizontal position. Because of the play in the connection between the diaphragm stem and the valve stem the movement of the diaphragm to the point where the lever is brought to a horizontal position will not aflect the valve, the latter remaining fully closed. If now the diaphragm continues to rise the headed end of its stem will exert a null on the valve stem and the valve will be lifted from its seat. The outer end of the lever bein now raised above a horizontal position, t a Weight 24.- Will roll toward the fulcrum allowing the full force of the unbalanced pressure to cause the valve to be quickly opened. The start of the weight toward the fulcrum is about simultaneous with the initial movement of thevalve. As this opening movement of the valve occurs the spring plungers are compressed by the upward passage of the-enlargement 8, again projecting to hold the valve in fully opened position. I u

The instant the valve opens the difi'erential pressure has changed from a maximum to some intermediate pressure without causing any change in the wide open position of the valve and this position of the valve will be maintained until the differential pressure falls to a minimum. When this minimum is reached the lever will descend and, as in the case of the raising of the lever, its initial movement will notafi'ect the position of the valve. It is only when the headed end of the diaphragm stem reaches the bottom of the recess of the conmotion 7 that the closing movement of the valve is started. Simultaneously with this starting of the valve the lever reaches its horizontal position and as it continues to move downwardly the weight 24 will roll to its outermostposition and the full 'force of the weight against the diminished unbalanced pressure will cause the valve to rapidly close.

claim as my invention:

1. Relief valve mechanism including a casing having an inlet and an outlet, a valve controlling such inlet and outlet, a diaphragm and a chamber therefor, said chamber'being connected on the upper side of said diaphragm with the outlet of a main conduit and on the underside of said diaphragm with the inlet of a"main-conduit, a connec tion between said 'dia hragm and said valve for opening said va ve when the difieren tial pressureon said diaphragm has reached a maximum and for closing said valve when the differential pressure is at a minimum, and means cooperating with the maximum ressure on said diaphragm to permit a quick opening of the valve and for quickly closing said valve when the difierential pressure is at a minimum, such means in part being adjustable to regulate the maximum and minimum differential pressures at which said valve shall open and close.

'2. Relief valve mechanism including a casing having an inlet and an outlet, a valve controlling such inlet and outlet, a diaphragm and a chamber therefor said chamher being connected on the upper side of said diaphragm with the outlet of a main conduit'and on the underside of said diaphragm with the inlet of a main conduit, a connection between said diaphragm and said valve for opening said valve when the differential pressure on said diaphragm has reached a maximum and for closing said valve when the differential pressure is at a minimum, means for adjustably establishing the maximum and minimum differential pressures at which said valve shall operate, such means in part cooperating with the maximum pressure on said diaphragm to permit a quick opening of the valve and for quickly closing said valve when the differential pressure is at a minimum, and means for maintaining said valve fully opened or closed.

3. Relief valve mechanism including a. casing having an inlet and an outlet, a valve controlling such inlet and outlet, a diaphragm and a chamber therefor, said chamber being connected on the upper side of said diaphragm with the outlet of a main conduit and on the underside of said diaphragm with the inlet of a main conduit, a connection between said diaphragm and said valve for opening and closing said valve, said connection permitting limited movement of said diaphragm independently of said valve to open said valve only when the differential pressure on the diaphragm has reached a maximum and to close said valve only when the differential pressure is casing having an inlet and an outlet, a valve controlling such inlet and outlet, a diaphragm and a chamber therefor, said chamer being connected on the upper side of said diaphragm with the outlet of a main conduit and on the underside of saiddiaphragm with the inlet of a main conduit, :1. connection between said dia hragm and said valve 'for opening said va ve when the differential pressure on said diaphragm has reached a maximum and for closin said valve when the differential pressure is at a. minimum, a lever connected with said diaphragm, and a relatively movable element on said lever adapted upon movement in one direction through the instrumentality of the maximum pressure on said diaphragm to permit a, quick opening of the valve and uplon'movement in the opposite direction w en the differential pressure on said diaphragm has reached a minimum to effect a quick closing of said valve.

5. Relief valve mechanism including a casing having an inlet and an outlet, a valve controlling such inlet and outlet, a. valve stem havin a circumferential bead, a diahragm an a chamber therefor, said chamber being connected on the upper side of said diaphragm withthe outlet of a main conduit and on the underside of said diaphragm with the inlet'of a main conduit, an interlocking connection between said diaphragm and said valve stem which permits limited movement of said diaphragm independently of said valve for o ening said valve only when the difl'erentia pressure on said diaphragm has reached a maximum and for closing said valve only when the difi'erential pressure is at a mlnimum, means cooperating with the maximum pressure on said diaphragm to permit a quick openin of the valve and for quickly closing sai valve when the differential pressure is at a minimum, and spring actuated members mounted in said casing and adapted to engage said valve stem beneath said head to hold said valve in full open position and above said bead to hold the valve in full closed position.

In testimony whereof I have signed this specification.

WILLIAM MoKEE. 

